CVE-2024-30621 identifies a stack overflow vulnerability in the Tenda AX1803 router firmware version 1.0.0.1. The vulnerability resides in the function fromAdvSetMacMtuWan, where improper handling of the serverName parameter allows an attacker to overflow the stack. This flaw is classified under CWE-121 (Stack-based Buffer Overflow). Exploitation requires no authentication and no user interaction, and can be performed remotely over the network. The impact is primarily on availability, as successful exploitation can cause the device or affected service to crash, leading to denial of service conditions. The CVSS v3.1 base score is 6.5, reflecting medium severity with attack vector as adjacent network (AV:A), low attack complexity (AC:L), no privileges required (PR:N), no user interaction (UI:N), unchanged scope (S:U), no confidentiality or integrity impact (C:N/I:N), and high availability impact (A:H). No patches or official fixes have been published at the time of disclosure, and no known exploits have been observed in the wild. The vulnerability affects a specific consumer router model, which is commonly deployed in home and small office environments. The lack of authentication requirement and ease of exploitation make this a notable risk for network availability disruption.

The primary impact of CVE-2024-30621 is denial of service due to the stack overflow causing crashes in the affected router. Organizations using Tenda AX1803 routers may experience network outages or degraded connectivity, impacting business operations, especially in environments relying on these routers for critical internet access or internal network segmentation. Although the vulnerability does not compromise confidentiality or integrity, the loss of availability can disrupt communications, remote work, and access to cloud services. The ease of exploitation without authentication increases the risk of opportunistic attacks from adjacent network attackers or compromised local devices. The absence of known exploits currently limits immediate widespread impact, but the vulnerability could be targeted in the future once exploit code becomes available. Small businesses and home users with limited IT support are particularly vulnerable due to the lack of patches and potential unawareness of the issue.

1. Immediately restrict access to the router's management interfaces from untrusted networks, especially disabling remote management features if enabled. 2. Segment the network to isolate the router management traffic from general user traffic to reduce exposure. 3. Monitor router logs and network traffic for signs of crashes or unusual behavior that may indicate exploitation attempts. 4. If possible, replace or upgrade affected Tenda AX1803 routers to models with updated firmware or from vendors with timely patching practices. 5. Employ network-level protections such as intrusion detection/prevention systems (IDS/IPS) to detect anomalous packets targeting the vulnerable parameter. 6. Engage with Tenda support channels to request firmware updates or security advisories. 7. Educate users and administrators about the risks of leaving router management interfaces exposed and the importance of timely updates. 8. Consider deploying network access control (NAC) to limit devices that can communicate with the router management interface.